After watchOS 10 I turned off auto updates.

Auto Sleep tracking and 7 day battery

I’ve used automation / shortcuts for over a year and it works pretty seamlessly. Just have to set a specific time every night for the shortcut to kick in, and manually flip off sleep mode whenever you wake up

Although I’ve learned if you’re working out when the shortcut kicks in, entering sleep mode will automatically end your workout but I’m rarely working out at 11pm so not a huge deal.